Seamless geocoding mapping method and system for side-scan sonar

Abstract

The invention provides a seamless geocoding mapping method and system for a side-scan sonar, and the method comprises the steps: reading the original data of a side-scan sonar image, and forming a waterfall image through horizontal stacking; extracting channel data; performing quality control and interpolation on the channel data, and calculating the position of the tow fish based on the consistency of the tow fish and the course of the ship body; calculating the echo position of the side-scan sonar image according to the tow fish position and the ship course; determining a mapsheet range according to the echo position, setting a mapping resolution, and determining a pixel space of the coded image; traversing and extracting two pairs of adjacent echoes on adjacent scanning lines in the waterfall image, determining four-corner pixel positions of the two pairs of echoes in a pixel space, and constructing a local grid cache region covering the four-corner pixel positions; and scanning the local grid cache region, carrying out XOR operation on a scanning result to obtain a gap pixel set, and carrying out intensity assignment on the gap pixel set to obtain a seamless side-scan sonar geocoded image.

Description

technical field [0001] The invention relates to the technical field of underwater sonar mapping, in particular to a method and system for seamless geocoding and mapping of side-scan sonar. Background technique [0002] The side-scan sonar system uses a double-line array to scan the seabed targets within a certain opening angle range below the towfish, forming time-series echoes distributed along the slant distance, which are displayed on the image as a vertical track direction centered on the towfish. The scanning lines are stacked vertically according to the navigation order to form a side-scan sonar waterfall image. [0003] The side-scan sonar waterfall image does not have an intuitive position and orientation, and the waterfall image needs to be geocoded for ease of use. Due to the limitation of ship speed change and distance mapping, the vertical and horizontal echo resolutions of side scan sonar are inconsistent, and there are gaps between adjacent scan lines of side ...

AI Technical Summary

Problems solved by technology

The data of the vertical track of the side scan sonar has a relatively high resolution. The above processing method will lose some details in the original data, and when the heading changes significantly, it will not improve the appearance of the edges on both sides of the scan line on the coded image. gaps and intersections

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